1. Field of the Invention
This invention relates to ceramics and more particularly to a brick and tile cutting and setting machine. Specifically this invention relates to the cutter wires for such a machine.
2. Description of the Prior Art
The use of automatic cutting and setting machinery in the brick and tile industry has become almost universal. These machines are designed so that long bars or slugs of extruded clay or shale are forced through a bank of multiple steel cutting wires spaced to slice the slugs into the desired brick or tile dimension. Traditionally, the cutting wire are supplied in standard 32" length with loops formed on either end for simple and convenient mounting on the cutting wire frame. It will be seen, that even though the cutting wires are quite long, only 8" (in the case of double high slug cutting), or 4" (single high mode), of the wire is actually used. When this short section near the center of the cutting wire wears thin and breaks, a great proportion of the wire, even though completely unused, must be discarded.
Successful operation of any automatic cutting and setting machine requires immediate shutdown of the entire extrusion line and handling system when a cutting wire breaks. Consequently, by far the major proportion of machine outage is due to broken cutting wires. On some plants, working hard, highly abrasive shales, loss of production due to cutting wire failure is very significant. Other plants working "smooth" or "soft" clays, the loss is not nearly so great. However, any clay or shale is inherently abrasive to some degrees so the broken cutting wire specter is universal in the clay products industry.
It is exceedingly rare for a new, full gauge cutting wire to break in service unless some foreign material is extruded in the clay slug. The wires commence to break after a number of slugs have been passed through the wire bank and the wires have become worn in a "knife blade" shape in cross section. This wearing of the cutting wires is particularly insidious because as the wire wears flat it tends to weave through the clay slug rather than slice cleanly through, resulting in crooked or wavy edges on the brick. Thus, in addition to the ever increasing danger of breakage as a cutting wire wears, poor quality brick are produced.
There is a time when the wires are sufficiently worn that it is desirable to replace all of the wires. This occurs regularly. The machine is out of operation when the wires are being replaced.
After I made this invention and before filing a patent application, a search was made in the U.S. Patent and Trademark Office upon this invention. This search revealed the following U.S. Pat. Nos.: Steele--1,555,769; Jimerson--2,074,695; Heft--2,302,371; Passarelli--2,443,928; Theirman--3,927,687.
Theirman discloses a dental floss advancer. Steele discloses a brick cutter that does not use an advancing wire. Jimerson discloses mining equipment for sawing pillars.
Heft shows a butter slicer. Passarelli discloses a manual cheese slicer.
In addition to that in the preparation of patent application the attorney preparing the patent application was aware of Jacobs Et Al Bobbin Hobble, U.S. Pat. No. 3,019,893 which discloses a hobble made of a transparent spring material to extend around a sewing machine bobbin to prevent the thread from being tangled when not in use.